Enfamil Standard Flow baby bottle nipples are ready-to-use, come individually wrapped, and vented to allow air flow while the baby is sucking. Standard Flow BPA free and latex free nipples are our medium flow nipples which are a good starting off place for most infants. They will fit most baby bottles with standard or classic size infant bottle openings, including our Nursette bottles and our ready to feed baby formula bottles, Enfamil plastic bottles, Enfamil Grad-U-Feed nursers, Mead Johnson Cleft lip/Palate Nursers, and Snappies.